The Water Clock Children’s Museum of Indianapolis displays time as colored & filled up water vessels – “Designed by French physicist and artist Bernard Gitton…The clock, which is 26.5 feet tall, uses 70 gallons of a solution of water, methyl alcohol and food coloring. The alcohol prevents algae and fungus from growing inside the pipes while the food coloring allows visitors to see the clock’s function more clearly.” – [via] – Link.